When a sample of water was boiled, it lathered more readily with soap. it can be concluded that the sample most likely contained

Answer Details

When water is boiled, it becomes more receptive to lathering with soap. This indicates that the sample contains calcium hydrogentrioxocarbonate (IV) (Ca(HCO₃)₂). Hard water contains calcium and magnesium ions which reacts with soap to form an insoluble precipitate (soap scum), which reduces the effectiveness of soap. Boiling hard water removes temporary hardness (calcium hydrogen-carbonate) by causing the bicarbonate ions to decompose and produce insoluble carbonate, which can be removed by filtration, leaving behind soft water that lathers more easily with soap.